Hexamethylene triperoxide diamine (HMTD) is a <!-- note to editors: "high explosive", not "highly explosive", is the correct term --> high explosive organic compound. HMTD is an organic peroxide, a heterocyclic compound with a cage-like structure. It is a primary explosive. It has been considered as an initiating explosive for blasting caps in the early part of 20th century, mostly because of its high initiating power (higher than that of mercury fulminate) and its inexpensive production. As such, it was quickly taken up as a primary explosive in mining applications. However, it has since been superseded by more (chemically) stable compounds such as dextrinated lead azide and DDNP (which contains no lead or mercury). HMTD is widely used in amateur-made blasting caps.
Preparation and structure
First synthesised in 1885 by the German chemist Ludwig Legler, HMTD may be prepared by the reaction of an aqueous solution of hydrogen peroxide and hexamine in the presence of an acid catalyst, such as citric acid, acetic acid or dilute sulfuric acid. The hydrogen peroxide needs to be at least 12% w/w concentration, as lower concentrations lead to poor yields. Citric acid is overall superior to other acids, providing a yield of up to about 50%.
The molecule adopts a cage-like structure with the nitrogen atoms having an unusual trigonal planar geometry.
Properties as an explosive
Like other organic peroxides, such as acetone peroxide (TATP), HMTD is unstable and detonated by shock, friction, static electricity discharges, concentrated sulfuric acid, strong UV radiation and heat. Common static electricity discharges have been reported to cause detonation. It attacks aluminum, tin, zinc, brass, copper, lead and iron.
HMTD is very unstable in storage, with decomposition rate increasing with temperature. Samples lost 79% of their weight in 300 days at , in 150 days at , and in only 5-20 days at . It is unstable even when stored under water. Nevertheless, HMTD is one of the three most widely used primary explosives in improvised, amateur made blasting caps, the others being TATP and silver acetylide.
HMTD is a common source of injury, particularly finger amputations, among amateur chemists. Most of these injuries are caused by small amounts of HMTD that inadvertently detonate in close proximity of fingers, since small amounts (grams) are generally not powerful enough to amputate fingers from distances larger than .
Reported explosive properties are a detonation velocity of in a column compressed to a density of and at a density of . Its power is 60% that of TNT in the Trauzl test.
and the 2016 New York and New Jersey bombings, as well as one of the components of the explosives attempted to be made by the neo-Nazi terrorist organization Atomwaffen Division in the United States.